Blood-derived serum albumin contributes to neurodegeneration via astroglial stress fiber formation.

Enhanced influx of blood-derived serum albumin into the brain is seen after blood-brain barrier disrupture and may induce neurodegeneration. The aim of the present study was to explore the effects of high levels of bovine serum albumin (BSA) on the survival of cholinergic neurons in organotypic brain slices of the basal nucleus of Meynert and in comparison in isolated primary astroglia. When brain slices were exposed to high BSA concentrations, a strong tissue shrinkage was observed accompanied with cholinergic cell death. The shrinkage was prevented by endothelial cell growth factor and heparin. In primary astrocytes, high BSA concentrations induced stress fiber formation, which was reduced by hydrocortisone or the phosphoinositol-3-kinase inhibitor LY294002. In conclusion, high BSA levels are neurotoxic for brain neurons. Cholinergic neurons are protected in an intact astroglial network, which might be of importance in neurodegenerative diseases, such as Alzheimer's disease.